gpio: tegra186: Fix chip_data type confusion
authorMarc Zyngier <maz@kernel.org>
Fri, 11 Feb 2022 09:39:04 +0000 (09:39 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 2 Mar 2022 10:48:10 +0000 (11:48 +0100)
commit83f331d1debb143f9d755b727009bc65028a382f
tree327d19e1a912aae8cc92d4f3fdaaf92a0b0dfa17
parenta157691554403140f26a821da38832b72bd83ac1
gpio: tegra186: Fix chip_data type confusion

commit d1e972ace42390de739cde87d96043dcbe502286 upstream.

The tegra186 GPIO driver makes the assumption that the pointer
returned by irq_data_get_irq_chip_data() is a pointer to a
tegra_gpio structure. Unfortunately, it is actually a pointer
to the inner gpio_chip structure, as mandated by the gpiolib
infrastructure. Nice try.

The saving grace is that the gpio_chip is the first member of
tegra_gpio, so the bug has gone undetected since... forever.

Fix it by performing a container_of() on the pointer. This results
in no additional code, and makes it possible to understand how
the whole thing works.

Fixes: 5b2b135a87fc ("gpio: Add Tegra186 support")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Link: https://lore.kernel.org/r/20220211093904.1112679-1-maz@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/gpio/gpio-tegra186.c